Winches employed for securing loads on the floor of a vehicle are generally attached to the side rail structure of the vehicle by welding or bolting. This approach has disadvantages of the heavier weight required for the welded portion of the winch as well as contact stress in this portion. Further, if the winch needs to be replaced, the removal of the welded portion involves damage to the side rail. In addition, the cost of assembly is increased with a welding or bolting attachment. Such prior art attachment systems are described in U.S. Pat. No. 5,433,565 issued Jul. 18, 1995 to Chan and U.S. Pat. No. 5,490,749 issued Feb. 13, 1996 to Arbues.